How Long is the Memory of a Goldfish?

Has anyone ever insultingly told you that you have the memory of a goldfish?

I hope you thanked them for the complement.


There’s this silly notion floating around that goldfish are creatures of very little brain power – they don’t ever get bored because every three seconds they forget everything and they aren’t really capable of intelligent behavior.

Nothing could be further from the truth!

And today we are going to show you the hard-core, no-nonsense scientific PROOF that goldfish are smarter than you think!

Keep reading to get the scoop.

Researching into Goldfish Memory Spans

A researcher offers his opinion regarding the stereotype:

“A lot of people have the image of a goldfish with a three-second memory – and that’s not the case at all. There is a lot of evidence now that fish are no dumber than birds or many mammals – and in many cases they are just as intelligent. They can learn their way around mazes, they can learn to recognise other fish, and they can remember which individuals are better competitors.” – Dr. Mike Webster (source)

This is backed up by the facts.

Take, for example, a 15 year old student named Rory from Australia who did a simple experiment to test goldfish memory capabilities.

“I decided to get a bit of red Lego and just feed them next to that. Every day I’d put it in and sprinkle food around it. At first they were a bit scared of it, a bit wary, but by the end of the three weeks, they were actually almost coming before I put the food in.”

The boy then waited nearly a week before putting the red Lego back in again.

“They remembered perfectly well. They actually had a time faster than the average of the three feeds before I left.”

This proved that the training not only stuck with the goldfish, but they could call it to mind at a later date – far beyond three seconds 😉

But we’re getting started:

Take, for instance, the findings of studies at Plymouth University that show how goldfish remembered things for 3 months and can even tell time!

Their fish needed to nudge a lever in order to get food.

The researchers then made it so the lever only worked for one hour every day.

Guess what?

Those goldfish learned to only pressed the lever in the right time frame.  At that feeding time, they even hovered around the lever in anticipation!

But if you STILL are in doubt…

Just listen to this last example:

Researchers in Israel trained some young fish for one month to come to food at the sound of a bell.

After that…

… They released the fish into the sea.

Now get this:

5 months later they played the sound over speakers.

And the fish all came swimming back!

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Chances are, the Memory of a Goldfish is FAR longer than 5 months…

All of the times in those tests were set as the goal.  Finding out when the fish actually forgot something wasn’t part of the test.

This means goldfish can possibly remember things for even longer.

For example:

As you may know, the carp is the granddaddy of the goldfish.


Goldfish are really modified carp, which look different on the outside but haven’t changed much on the inside (aside from perhaps more compressed organs in fancy goldfish, which makes them more sensitive when it comes to diet.)

Interestingly enough, carps that were caught on the hooks of a fishing rod avoided lures for at least a year!

So, exactly how long is a goldfish memory?

We don’t know 100% for sure…

It hasn’t been tested for long enough to find when goldfish actually forget something.

But judging by the evidence we’ve looked at, it’s safe to say they have as good a memory as most other small pets, which is at least several months if not YEARS.

Hopefully this article brings to light the nail in the coffin for this 3 second goldfish memory fallacy.

Here’s The Most Poisonous Part About This Memory Myth…

People use this faulty notion about goldfish to justify keeping them in poor living conditions.

After all, if fish are so dumb, they don’t really need much space or a stimulating environment.

Case in point:

Even young Rory sees the faulty conclusion people come to when they see goldfish as pea-brained dunces…

“We are told that a goldfish has a memory span of less than three seconds… I wanted to challenge this theory as I believe it is a myth intended to make us feel less guilty about keeping fish in small tanks.”

A bowl should be plenty interesting, right?


Bowls are terrible for care reasons.  But they are also boring and cramped living quarters for their poor inhabitants.


As in most cases, the goldfish is a sadly misunderstood pet (maybe one of the most misunderstood).  To many people, they are not even seen as pets… just a pretty decoration to have around the house.

Goldfish get much larger than most people know, and they need lots of space to thrive physically and mentally.

Things really change when you realize a goldfish memory may span MONTHS – not seconds.

Think about it:

Would you be happy to live in a closet your whole life?

Then don’t think your fish will be!

Most who keep goldfish discover their pet is very quick to catch on where the food comes on, sometimes even being trained to beg at one side of the aquarium!

Dr. Culum Brown has studied fish behavior for over a decade and maintains that fish are intelligent creatures who learn the lifelong skills of avoiding predators and foraging for food.

He has this to say about whether or not it is cruel to keep fish in small spaces to live:

“Definitely – I think the more complicated you make your fish tank, the happier your fish is gonna be.”  In fact, the best thing to do is to keep changing it around, so make it interesting for them. You’ll find that if you do that, your goldfish will be much more active and much happier in general.”

For more information on giving your goldfish the best life possible, you really need to check out our book, The Truth About Goldfish.

It has everything you need to know about setting up the perfect and safe environment for your fish, so it can live a healthy, happy life for many years to come.

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I hear from so many distressed owners who are horrified at the thought that their care of their pet is really causing them damage, so I decided to put my 10 years of goldfish knowledge into one powerful resource.

I’d encourage you to check it out 🙂

But Don’t Goldfish Have Tiny Brains?

Fun fact:

A fish’s brain is 380,000 times smaller than the brain of a human baby.

So there’s no denying it is tiny.

It is true that they have small brains, but only in comparison to larger living things.

Their brain is sized in proportion to the rest of them, which is just as small in comparison to a person.

The bottom line?

Small does not mean stupid!

There are plenty of other animals, such as mice, birds and reptiles which have the ability to retain information for extended lengths of time.

Now I want to Hear from You:

Are you surprised to learn the mental capabilities of the world’s most popular  finned friend?

I hope you are excited to know the TRUTH about the three-second goldfish memory.

Maybe you have experience in teaching your goldfish to remember something.


Either way, leave your comment below to let me know what you think![/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

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  1. Mateusz Jozwiak June 2, 2017 at 7:35 pm - Reply

    My 2 goldfish always swim around a corner where we always feed them, and they also follow me around everywhere i go well… only around the aquarium. Love this website,bought the book!

    • Pure Goldfish
      Pure Goldfish June 17, 2017 at 11:12 pm - Reply

      How cute, Mateusz! They do have such personalities, don’t they. Thanks for your support. 🙂

  2. Chicken June 2, 2017 at 8:59 pm - Reply

    my proof that goldfish actually remember things: When ever I’m feeding the smaller ones, I tend to use a the net to shoo the big fish away from the food so that the small fish actually have a chance of getting food. Now whenever I place the net in the tank, I don’t even need to hold onto it; I just need to place the net into the tank and the big fish automatically go to the opposite side of the tank. Although that doesn’t stop some of them from sniffing around the net!

    • Pure Goldfish
      Pure Goldfish June 17, 2017 at 11:12 pm - Reply

      I believe it! Goldfish are so much smarter than people give them credit for.

  3. Person August 22, 2017 at 11:04 pm - Reply

    Sadly, a whole ton of people still believe it

    Rating: 4.5
    • Pure Goldfish
      Pure Goldfish August 26, 2017 at 8:53 pm - Reply

      Very true 🙁

  4. Olafs March 26, 2018 at 5:57 pm - Reply

    This actually happened: One of my fish was lying on its side at the bottom of the aquarium, appearing moribund. One of the other fish hovered over it fanning it with its fins as if to resuscitate it. I reached into the tank, lifted the sick fish and began pushing it around the tank. When I stopped, the other fish took over and, to my astonishment began pushing it around in the same pattern that I had been using. The sick fish recovered!
    My fish eat out of my fingers – they were suspicious at first.

    Rating: 4.5
    • Pure Goldfish
      Pure Goldfish April 1, 2018 at 10:31 pm - Reply

      Goldfish sure are amazing! Thanks for sharing your story, Olafs!

  5. Wyatt June 1, 2018 at 9:32 pm - Reply

    I am doing a science fair and my question is on goldfish lifespans. My goldfish is being trained to associate a bell ringing with feeding time, and whenever I ring the bell, he comes to the top of the tank. This website helped me form my hypothesis. Fish are so misunderstood, and my fish get to enjoy a 55 gallon, but there are other fish in tiny bowls. I wish I could help. My fish says hi! 😀

    Rating: 5
    • Pure Goldfish
      Pure Goldfish June 3, 2018 at 11:02 pm - Reply

      Totally agree with you, Wyatt. Cool experiment!

  6. Chas August 9, 2018 at 1:32 am - Reply

    There is a difference between memory of an isolated event, and conditioned memory (repeated associative memories, which enable us to train or condition small-brained animals to stimuli). There can be little doubt that the human brain is at the apex of memory capability far above almost all other animals. But there are a few, such as dolphins, whose long-term memory capabilities are very close to humans.

    Rating: 4.5
    • Pure Goldfish
      Pure Goldfish August 12, 2018 at 9:50 pm - Reply

      Interesting observations, Chas!

  7. Alice October 23, 2018 at 9:00 pm - Reply

    I am doing a project on the myth of \”Goldfish have short memories\”. I was wondering if you knew how this myth originated, or began? Also, I foung this article very helpful! 🙂

    • Pure Goldfish
      Pure Goldfish October 25, 2018 at 4:42 pm - Reply

      Honestly I have no idea, sorry! Maybe whoever came up with that never kept goldfish 😉

    • Anonymous October 29, 2018 at 10:07 pm - Reply

      I have that exact same project and I think I know you from school. I don’t know how it started though 🙁

      Rating: 4.5

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